LIFE: ITS ORIGIN AND NATURE 39 
as the quantity of them required would always 
be exactly proportional to the amount of work 
done. Nevertheless, this would be a very in¬ 
consequent assumption. So it would be also if 
we were to infer, because the motors at the 
bottom of the electric tram-car waste as they 
are used by electric energy, as the means of 
doing work, and if we could arrange that this 
waste should be made good by some self-acting 
mechanism—as well might we imagine that the 
steel particles flowing in were the cause of the 
work done, as that the food is the cause of the 
work done by the human body. Yet this is the 
assumption invariably made by modern scien¬ 
tists. 
In other words, food does not cause or create 
the bodily energy—any more than the steel par¬ 
ticles cause the digging or the power contained 
within the electric motor. Food merely repairs 
the body —through which the energy flows; and 
the more work done, the greater the amount of 
food needed, to repair the loss. Hence the 
equivalence, but not the causation! 
Are there any facts which tell in favor of this 
view, as opposed to that commonly held? There 
are several, among which I might mention the 
following: 
(1) Whenever we become tired, as the result 
of the day’s work, we must retire to the bed¬ 
room and not the dining room, in order to 
recover our strength and energy. No matter 
how much food we eat, how much exercise we 
take, how thoroughly we breathe, or how com¬ 
pletely this food material may be oxidized, 
there always comes a time, nevertheless, when 
